Method and apparatus for stripping casting



June 28, 1960 e. B. MEGINNIS METHOD AND APPARATUS FOR STRIPPING cAsTmcFiled Aug. Tea, 1957 I .6 A g F v \:/W.\/\!\M\//4 \\\\\.\\\-/W/.W R. WY. L a W. m H 1 lll I: w A I A WW ,4 Mr A A 1!. A .A r A ll! M ill A. 2d a. I. Z MW .6 fi W v, i 5 i f 2 A 2., I w 9 A v f- A III AW] I Z I, w!A .A II A I1 I! v 2 w a M MAT/lib United States METHOD AND APPARATUS FORSTRIPPING CASTING Filed Aug. 28, 1957, Ser. No. 680,799

4 Claims. (Cl. 22-1) The present invention relates to a method andapparatus for stripping a metal tube used in forming a cast object andwhich method and apparatus maximizes the material salvageable in theformation of such object.

In the process of forming a casting in which a steel tube or cup is usedin conjunction with a material to which an additional material is to bebonded, it has heretofore been the practice after the casting has beencompleted to machine away thesteel tube or cup. In this process therough casting including steel cup is non-concentric, none the less, aconcentrically moving cutting tool is used to remove the cup which hasresulted in scrap material in which the steel tubing cuttings areinextricably mixed with the metal thereadjacent in the casting with aresultant non-salvageable waste product. Further, the necessity formachining away the steel tubing has occasioned high machine tool wearfurther adding to the cost of the casting forming process.

In the present invention a method and apparatus have been devised inwhich it is possible to practically completely salvage the cast materialas scrap and further in which no machining operation is necessary inseparating the steel tubing from the remainder of the casting.

In the subject invention the steel cup or tube is reverse drawn relativeto the casting which turns the cup inside out and in so doingmechanically separates the tubing from the casting in such a way thatvery little casting material adheres to the tubing. Further, when thetubing or cup is practically completely inverted the tube is sheared offfrom the remainder of the casting which may thereafter be finished tosize.

It is also an object of the present invention to provide a punch and dieapparatus in which the expendable steel cup is automatically strippedfrom the punch after the tube has been sheared and further in which thecasting is stripped from the punch when the latter is withdrawn from thedie. v

The details as well as other objects and advantages of the presentinvention will be apparent from a perusal of the description whichfollows.

In the drawings:

Figure l is a partially sectioned view of the subject apparatus; V

Figure 2 is a fragmentary partial section of the apparatus prior to thestripping of the tube from the casting; and

Figure 3 is a partially sectioned view of the apparatus just prior tothe completion of the stripping operation.

A punch press is shown generally at in Figure 1 and save as will beparticularly described and claimed constitutes no part of the presentinvention. Press 10 includes a punch member 12 suitably mounted thereinand adapted to be moved downwardly to cooperate, in the manner to bedescribed, with a die 14.

, A typical cast member with which the subject apparatus may be employedis shown generally at 16. The casting 16 in this instance, includes asteel backing member 18 on which a bronze face 20 is adapted to be cast.

atent O F 2,942,311 Patented June 28, "1960 To cast the bronze face 20onto member 18, a steel tube or cup-shaped member 22 having a flange 24at its lower end is welded into a recess 26 formed in one end of thebacking member. In this way an annular space is formed between member 18and cup 22 and into which space molten bronze is poured. The bronzethereafter forms an alloy bond with back member 18. It is to beunderstood that the particular metals noted are merely for illustrativepurposes and the present apparatus and method may be utilized with anycasting in which it is'desired to remove an expendable and non-frangiblecore member therefrom.

After the casting is poured and has solidified it is mounted on the die14 and more particularly on the shear ring 28.

The punch 12 includes a main shank portion 30 which terminates in atapered end section 32. End section 32 includes a recess 34 formedtherein and adapted to s1idably receive a piston or ejector member 36.The piston member 36 is suitably recessed and bored at 38 to permit astud 40 to pass therethrough and be threaded into a threaded bore 42 inthe tapered section 32 to prevent the ejector piston 36 from becomingdetached from the punch 12. A plurality of such studs may be employed ifnecessary.

A plurality of matching recesses 44 and 46 are formed in the taperedsection 32 and piston 36 and are adapted to receive therewithincompression spring members 48. For reasons to be described, the springmembers 48 are adapted to bias piston member 36 in an extended positionrelative to the tapered section 32. Punch 12 is formed in a way toprovide a shearing collar 50 disposed intermediate sections 30 and 32thereof.

As best seen in Figure 3, as the punch 12 is moved downwardly, thepiston 36 engages cup-shaped member 22 and in so doing the piston ismoved axially into the punch recess 34, as seen in Figure 3. Thecontinued downward movement of punch 12 will cause the steel cup or tubemember. to be turned inside out and stripped away from the material 20previously cast to the backing member 18. In thus reversely drawing orinverting the tube 22 very little of the material 20 will adherethereto.

When the cup or tube 22 is completely inverted the shearing collar 50approaches the shearing ring 22 of die '14 and continued movement willcause the cup to be sheared ofi along flange 24. Due to the tapered formof punch section 32 and the strength of spring members 48, the ejectormember 36 will cause the sheared tube 22 to be stripped from punchsection 32.

A ring 52 is suitably fixed to the punch shank 30 for movementtherewith. A corresponding ring 54 is mounted on the punch shank 30 butis adapted to slide axially with respect thereto. Slidable ring 54 isnormally axially spaced from fixed ring 52 and connected thereto througha plurality of circumferentially spaced spring elements 56. It isintended to provide means such as studs, not shown, loosely connectedbetween rings 52 and 54 to prevent the rings from separating beyond thatamount indicated in Figure 2. Y

The purpose of the ring members 52 and 54 is to insure that the casting16 will be stripped from the punch 12 when the latter is withdrawn fromthe die 14. Thus, as will be best seen in Figure 3, as the shearingcollar 50 approaches the shear ring 28, the movable ring 54 will engagethe upper end of the casting member 16. As the punch continues itsdownward movement the ring 52 will be moved axially toward the movablering 54 and in so doing will compress the spring members 56. As thepunch 12 is withdrawn from the die 14 at the end of the shearingoperation, the spring members 56 will cause the movable ring 54 to exertan appreciable axial force against the casting and in so doing insurethat the latter will not adhere to the punch when the latter isWithdrawn preliminary to starting another stripping operation.

Thus the punch 12 includes a pair of stripping devices, piston 36 andrings 52 and 54, which are adapted respectively to strip the expendedtube 22 from the tapered section 32 of the punch and also to strip thecasting, per se, from the shearing collar 51L As seen in Figure 1, anopen trap or chute 58 is formed below the die member 14 in the bedof'punch press in order that the expended caps 22 may be ejected fromthe front of the press and thereby not inhibit the continuous operationof the subject apparatus.

It is apparent that various structural modifications may be made in thesubject apparatus within the scope of the inventive concept hereinaboveset forth.

I claim:

1. An apparatus for removing a cup shaped liner from a hollow castmember bonded thereto comprising a die adapted to support said memberwith the open cup end adjacent the die, a punch,- piston means slidablymounted in the punch, means biasing said piston means axially away fromthe punch, said piston means being adapted to engage said cup during themovement of said punch toward said die whereby the piston means is movedinto axially abutting relation with said punch, a shearing collardisposed on said punch intermediate the ends thereof, said collar beingadapted to engage with and shear off said liner after said punch hasinverted and mechanically separated the liner from said member, saidbiasing means being adapted to move said piston means to strip saidliner from the punch after shearing, and means adapted to strip saidmember from said punch when the latter is withdrawn from said die.

2. An apparatus as defined in claim 1 in which said member strippingmeans comprises a first collar fixed to said punch, a second collarslidably supported on said punch, said collars being disposed on saidpunch anteriorly of shearing collar, and means for resilientlyconnecting said first and second collars in axially spaced relation.

3. An apparatus for removing a cup shaped liner from a cast membercomprising a die adapted to support said member with the open cup endadjacent the die, a punch means adapted to engage the closed end of saidcup and invert the latter in moving toward said die, a shearing collardisposed on said punch means intermediate. the ends thereof, said collarbeing adapted to shear off said liner after said punch means hasinverted and mechanically separated the liner from said member, meansfor stripping said sheared cup from said punch means, and additionalmeans adapted to strip said member from said shearing collar when thepunch means is withdrawn from said die. 7

4. An apparatus as defined in claim 3 in which said punch means includesa tapered end section for coacting with said liner, and further in whichsaid sheared cup stripping means is disposed in a recess formed in saidtapered end section and comprises a piston slidably supported within therecess for axial movement relative to the punch, spring means biasingsaid piston axially away from said punch, and stop means for limitingthe axially away movement of the piston.

References Cited in the file of this patent UNITED STATES PATENTS1,393,195 Bradley Oct. 11, 1921 1,630,715 Nice May 31, 1927 2,031,982Salzman Feb. 25, 1936 2,330,762 Tooker Sept. 28, 1943 2,422,952 DakinJune 24, 1947 2,730,763 Brundage Jan. 17, 1956 2,796,634 Chellis June25, 1957

